title: Batch variations.
abstract: One of the basic principles in the investigation of suspected contact dermatitis is always to test with the patient's "own" product or chemical, the one to which he or she was actually exposed. An equally basic second principle is not to rely solely on a positive test reaction. The author discusses a case of contact dermatitis involving only certain batches of a particular branded product.
authors.affiliation: Institute of Dermatology, London, England.
authors.forename: C D
authors.initials: CD
authors.lastname: Calnan
mesh_terms: D003358:Cosmetics / Q000009:adverse effects* / Q000494:pharmacology; D003877:Dermatitis, Contact / Q000276:immunology*; D004339:Drug Compounding; D005148:Facial Dermatoses / Q000139:chemically induced* / Q000276:immunology; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D007509:Irritants; D008875:Middle Aged; D010328:Patch Tests / Q000379:methods*; D012882:Skin Tests / Q000379:methods*
chemical_list: D003358:Cosmetics; D007509:Irritants